Blade Runner skies over San Francisco. Moonscapes of ash and blackened trees. Last year’s staggering fire season offered plenty of scenes of destruction, but some of the fires’ worst effects are invisible. In San Francisco, Seattle, Portland, Ore., and other western cities, wildfire smoke caused some of the world’s worst air pollution for weeks on end. Prolonged expo- sure to smoke triggers long-term lung damage, and is particularly worrisome for younger and older people, as well as those with asthma and other lung conditions. Wildfire smoke exposure is also linked to cardiovascular issues and increased susceptibility to the flu and COVID-19.
The wildfires have also put regional water supplies — including those we rely on for drinking water — in danger. Incinerated watersheds can fill waterways with debris and wash arsenic and other toxins from mines, towns and industrial sites into streams and rivers. Heat-damaged plastics and building materials, such as plastic water pipes, can also leach poisonous chemicals. After California’s 2017 Tubbs and 2018 Camp wildfires, the potent carcinogen benzene was found in water at levels that could cause immediate harm, along with a cocktail of other dangerous compounds. Limiting smoke exposure and improving building codes can mitigate these risks — but the only way to tackle them in the long-term is with climate action and climate-resilient forestry.